Broadband Satellite Communication (SATCOM) in the polar regions of the world remains an elusive but increasingly necessary form of communication. Coverage is virtually non-existent with exception of some attempts used mostly for narrowband telemetry and geographical sensing. One problem with polar SATCOM may stem from the fact that Geosynchronous Equatorial Orbit (GEO) Satellite Vehicles (SAT) hosting broadband transponders do not have a line-of-sight within the Polar Regions (above/below approximately 70 degrees North/South earth latitude). Aircraft and ground stations within the Polar Regions (and other regions not having line of sight with a GEO SAT) requiring Radio Frequency (RF) contact with the remainder of the world are left without broadband options.
In addition, aircraft and stations may function with an operable antenna designed for reception of a GEO satellite signal. Such antennas may have limited reception angle for receiving the GEO based signal. For example, an aircraft may possess an antenna limited to a reception angle of +/−75 degrees from vertical. Any signal greater than 75 degrees from vertical may not be adequately received by the aircraft. Traditional antennas are usually bound by mechanical and physical limits from achieving 90 degrees (or below the horizon) pointing.
Traditional antenna structures may require significant mechanical positioning hardware to maintain function. Antenna positioning gimbals and motors required to physically point an antenna element in a specific direction add weight and power to an antenna structure. Such heavy antenna elements may be prohibitively heavy for cost effective launch and mechanically intensive for long term maintenance onboard satellite vehicles.
Satellite vehicles may possess additional payload and infrastructure beyond that for which the SAT may be designed. Such additional infrastructure may be available for communication elements falling within the specific constraints (size, weight, power) set out by the owner of the SAT.
The cost to launch a constellation of SATs for one specific purpose (e.g. communications with Polar Regions, other regions lacking line-of-sight with a GEO SAT) may be prohibitive. Therefore, those entities desirous of access to SAT infrastructure may combine a variety of elements onboard a single or already operational constellation of SAT.
Some attempts at Polar Region communication via SATs lack the desired bandwidth and/or find limited operational success. Some of these traditional attempts may describe a radio receiver/transmitter onboard a Low Earth Orbit (LEO), Medium Earth Orbit (MEO) and High Earth Orbit (HEO) SAT. Such a radio receiver/transmitter requires a processor intensive demodulation of the received signal straining the limited processing capability and power available onboard the SAT. With the demodulation requirements also comes limited bandwidth capability.
Additional communication attempts may be limited by pure geometry. The attempts provide less than a full coverage of the Polar Regions. The limitations of these attempts may stem from inadequate geometry coverage since they use a low altitude satellite incapable of the geometry required for full Polar Region coverage.
Therefore, a need remains for a satellite based system and related method for successful satellite vehicle based relay of a signal between a GEO satellite vehicle and a transceiver located in the region lacking GEO signal coverage.